Spark-trouble locator



S. P. LANGMAID AND L. A WALTON.

SPARK TROUBLE LOCATOR. APPLICATION FILED'JUNE 1. 1920.

Patented Apr. 26, 1921.

III/illlllllll E I r Leonard A. Walz oza Samuel R. llazz o'rzza'af.

SAMUEL P. LANGMAID AND LEONARD A. WALTON, OF SEATTLE, WASHINGTON.

SPARK-TROUBLE LOOATOR.

atc es.

Specification of Letters Patent.

Patented Apr. 26, 1921.

Application filed September 1, 1920. Serial No. 407,454.

dash of automobiles and the like, to provide visual indication at all times of the operating condition of the spark plugs of the engine.

The improved indicator comprises a memher having cont-acts arranged to provide a gap in the circuit conductor from the coil or coils, or the distributer to the spark plugs, so that there is visual indication of the sparking action of each particular plug. The indicator also includes a ground wire having a slightly greater gap break with each of the leading-in wires of the indicator, so that in the event of an interruption of the current to the spark plugs, or break in the plug, the current, through the indicator,

will jump the gap to the ground wire, and

thereby indicate the failure of operation of the particular spark plug.

In the drawings Figure 1 is a plan of the improved indicator.

Fig. 2 is a vertical central section of the same.

-Fig. 3 is a broken elevation showing the indicator in place on the vehicle (lash.

The improved indicator comprises what may be termed a base 1, of insulating mate rial, the base being preferably circular in plan and having an annular edge rib 2 on the upper surface. A ground contact post 3 is passed centrally through the base, having an appropriate contact head 4 on its upper end, resting squarely on the base. The post 3 is secured in place by nuts a seated in a; recess 6 in the under surface of the base, these nuts also serving as a means for connecting a ground Wire 7 to said ground post 3. A series of contact posts 8, one for each cylinder of the engine is arranged in an annular row, concentric with the ground post 3, and spaced equal distances apart. These posts 8, which will be hereinafter termed leading-in posts, are connected-re spectively by wires 9, to the particular coils,

or to the contact points in the usual distributer head, according to which type of current distribution is used in the partlcular machine. The posts 8 have contact heads 11 of appropriate form resting upon the upper surface of the base, and are held in place by nuts 10, seating in recesses 12 in the lower surface of the base, these nuts also serving to secure the Wires 9 to the posts 8. I

Surrounding and concentric with the posts 8, are a second series of posts 13, secured in place by nuts 14. seating in recesses 15 in the lower surface of the base, these posts 13 serving as contacts posts for, and being connected to the respective spark plugs by conductors 16, secured by the nuts 14. These posts 13 hereinafter termed the leading-out posts, are arranged in an annular series beyond the posts 8, and preferably in radial alinement respectivel with the posts 8.

The upper end 0 the ground post 3 is provided with a star-shaped contact member 17, having a point 18, extended toward and providing a suitable air gap withthe upper end of the adjacent post 8. Similar starshaped contacts 19 are provided on the upper end of each of the leading-outposts 13, but these contacts 19, which may have any number of points desired, are mounted eccentrically on the posts 13, so that one or other of the points may be given any de sired air gap disposition with the adjacent post 8.

Assuming the parts arranged and connected as described, the indicator, which is secured'at a convenient place on the dash of the post 8 corresponding to that particular plug will follow the next shortest path of exit, that is, to the point of the starshaped contact 17 of the round post 3. This spark of course is visib e and will not only indicate-trouble in the particular spark plug circuit, but will of course specifically indicate the s ark pl involved. The star contacts 19 o the lea mg-out posts provide an additional gap in the spark plug circuit with the well known effect of intensifying the current between the spark plug points. Of course it is understood that the gap between the leading-in posts and the ground post is at all times greater. than the gap between the leading-out posts and the leading-in posts.

If desired and aspreterred, the indicator is protected without interfering with its visibility by providing a glass plate 21, to overlle the upper surface of the base, and rest upon the rib 2, a cap 22 having a central opening 23 being threaded to the'base at 24, and securing the glass cover in place. By this arrangement the sparking terminals of the indicator are protected, and yet readily accessible when desired for adjustment or repair.

Claim:

An indicator for spark plug circuits in cluding an insulating base, a ground post arranged therein, a series of leading-incit cuit posts arranged in concentric relation member carried by the upper end of the ground post.

In testimony whereof we afiix our signatures.

SAMUEL P. LANGMAID; LEONARD A. WALTON. 

